CONCORD — Exeter Hospital is no longer cooperating with a public health investigation into the hepatitis C outbreak that surfaced earlier this year, according to the New Hampshire attorney general and officials from the Department of Health and Human Services.

Investigators from DHHS have effectively been denied access to Exeter Hospital's medical records since July 27, according to court documents filed by the attorney general's office on Tuesday.

Health officials are still trying to determine the scope of the hepatitis C outbreak, which surfaced in May, and has led to infections in at least 32 Exeter Hospital patients.

A former Exeter Hospital technician has been charged with spreading the virus. He is accused of stealing hospital drugs, injecting himself, then placing syringes contaminated with his blood back into the laboratory, where they were used on patients.

The technician, David Kwiatkowski, was arrested in July on federal drug tampering charges. The 33-year-old Michigan native denies the charges and is awaiting trial.

Kwiatkowski, a traveling medical technician, worked in at least 19 hospitals in eight states between 2003 and 2012. His arrest has touched off new rounds of hepatitis C testing among thousands of patients who were treated at facilities where Kwiatkowski was employed.

Kwiatkowski worked inside Exeter Hospital's cardiac catheterization laboratory from April 2011 until the hepatitis C outbreak came to light in May 2012.

The hospital is now engaged in a legal tussle with officials from the New Hampshire Division of Public Health Services, who are trying to determine whether any additional Exeter Hospital patients were infected with the potentially fatal liver disease.

Exeter Hospital is asking a superior court judge to block state health officials from accessing its medical records unless the state first divulges what it's looking for. The hospital says the state has requested broad access to records that contain confidential health information. Releasing the information would constitute a breach of both state and federal laws, according to the hospital.

In motions filed Tuesday in Merrimack Superior Court, staffers from the attorney general's office refuted that claim. They argue state and federal laws expressly provide health officials with the power to review medical records amid a viral outbreak. Questions remain regarding the "mode of transmission and the scope of the outbreak," according to the attorney general's office, which is asking a judge to reject Exeter Hospital's request.

"This is an ongoing investigation that will require gathering additional information from Exeter Hospital, its employees and regional providers as well as state and federal agencies ... including, but not limited to, information contained in medical records maintained by Exeter Hospital," reads a motion filed by the state.

The hospital was initially cooperative with the state's requests. In May, June and July, health investigators were granted permission to log into the hospital's medical records using an employee's credentials, according to court documents. They accessed the hospital database at least nine times without objection, and also obtained physical records relating to the cardiac catheterization laboratory and the hospital's medication dispensing system.

But things changed in July. Exeter Hospital began asking state officials to detail the facts they were uncovering through the investigation, including the results of widespread hepatitis C screening among former Exeter Hospital patients.

When the state refused to share the information, Exeter Hospital "began resisting public health's requests," according to a memorandum of law filed by the attorney general's office. The hospital began preventing investigators from speaking with Exeter Hospital employees without a handler from the hospital present, and the hospital refused to grant access to medical records unless the state could prove the information it sought was "definitely linked" to the hepatitis C outbreak, according to the memo.

"In other words, Exeter Hospital obstructed access to medical records except for those of patients within the established cluster," of hepatitis C outbreak victims, the memorandum states.

In August, state health officials were asked to sign a legal agreement in order to continue accessing the hospital's electronic database. Those who signed the agreement were granted individual user names and passwords, which could be used to help the hospital track which patient information was being accessed.

However, the hospital and the state still disagreed about whether investigators should be required to provide evidence the records they were seeking were tied to the hepatitis C outbreak.

The situation came to a head on Aug. 24, when a state worker traveled to Exeter Hospital to collect patient records. The worker was met by an Exeter Hospital attorney who told her she would need to spell out what she was looking for before she would be granted access to medical records, according to an affidavit by New Hampshire State Epidemiologist Dr. Sharon Alroy-Preis.

The hospital filed a petition in Merrimack Superior Court on Aug. 29 asking a judge to grant a protective order shielding its medical records. It is now using the litigation as "an excuse to absolutely refuse to provide any information to Public Health," according to the affidavit.

State health officials argue medical records are a vital component of their investigation, since some patients who were potentially exposed to the virus might have already cleared it from their bodies.

DHHS launched a widespread hepatitis C screening program after the outbreak was detected in May. At least 1,066 patients who were treated at the cardiac catheterization laboratory and 78 employees who worked there have been tested.

Genetic testing is still under way on a new batch of blood samples collected from thousands more patients who were treated in other parts of the hospital.

The state has identified at least 28 former Exeter Hospital patients who appear to have cleared a hepatitis C infection, and genetic testing cannot be used to determine whether they were carrying the same strain of the virus as the other 32 patients who are linked with the outbreak, according to Alroy-Preis.